Abstract—In this work, we study the parameters of microseismic noise in the vicinity of the Chilean subduction zone in order to detect oscillations of a block–fault system, similar to those identified by processing the results of the previous laboratory experiment. The analysis is based on the data recorded by the broadband seismic stations of the international seismic network IRIS. We calculated the

Abstract—This work is devoted to constructing parametric mathematical models of effective elastic properties of carbonate rocks based on the effective medium theory (petroelastic models). These models have recently been particularly in demand for exploration geophysics because they link the elastic properties of hydrocarbon reservoir rocks with the parameters of the void space—the shape and volume

Abstract—We show that a solution of the system of three-dimensional equations of ideal magnetohydrodynamics is analytic in the spatial and temporal variables on a certain time interval with a strictly positive length provided that the initial flow velocity and magnetic field are analytic functions of spatial variables. Utilizing the property of frozenness of the magnetic field, we construct time Taylor

Abstract—A technique is proposed for joint inversion of the surface-wave velocity dispersion data from long travelpaths and the results of the receiver function method. The technique is based on a modification of a surface-wave tomography procedure and allows for the use of the data not only from travelpaths but also obtained at individual isolated points. Initially, the data are reduced to a single

Abstract—Empirical comparative study of the modern global models of the Earth’s gravity field (EGF) in the form of geopotential spherical harmonics is carried out. The importance and topicality of this study is associated with the growing number of models and strengthening the requirements to the modeling results. The obtained comparative characteristics are based on the results of statistical processing

Abstract—We present the results of magnetovariational soundings at two sites (Tiksi Observatory and Kotelny Island in the Laptev Sea region of the Arctic) and their three-dimensional (3D) inversion using the ModEM program. In the models obtained by the inversion, the conductive heterogeneities are present in the regions of the both sites down to a depth of 200 km in the region of the observatory and

Abstract—Based on the distribution of mantle seismicity and the sets of focal mechanisms of the earthquakes, the existence and deformation type of an allantoid mantle body within the eastern part of the Caucasus Isthmus is established. The body is inclined and plunges from the southeast to the northwest to a depth of 160 km. The shape of the mantle body and the type of its stress state which is fundamentally

Abstract—Statistical analysis of the focal mechanisms of the earthquakes based on the ISC standard catalog for 2001 to 2017 is carried out in the spatiotemporal vicinity of epicentral zone of the catastrophic seismic event of 2011 with Mw = 9.0 in Tohoku, Japan. It is established that during the 10-year period preceding this earthquake, more than 80% of the intermediate (B) axes of the focal mechanisms

Abstract—Two methods for estimating station anomalies in teleseismic P- and S-wave traveltimes are considered. Both methods employ traveltimes of the conversions from the upper boundary of the mantle transition zone. The first method directly uses traveltimes of the converted waves; in the second method, the sought parameters are estimated based on a simple two-layer model. The both approaches yield

Abstract—The archaeomagnetic study of ceramic material from Veksa III archaeological site (φ = 59°17′ N, λ = 40°10′ E) yield the data on the intensity of geomagnetic field in the V–III millennia B.C. in the Russian Plain. The combined results from the material of the Veksa III and Sakhtysh I sites (φ = 56°48′ N, λ = 40°33′ E) suggest that in the studied time interval, the intensity of the geomagnetic

Abstract—In this paper, we consider the problem of recording and processing the microseismic data with their subsequent interpretation and making the decisions concerning the probable threats associated with the violation of integrity of terrestrial environment due to mining activity. These decisions are made based on the detection of microseismic sources and recognition of their types by processing

Abstract—For determining the focal mechanism and source depth of an earthquake, a frequent practice is to use surface wave records which can be highly noisy. In this case, these records should be preliminarily selected and filtered in a certain spectral band using a frequency-time analysis program. In this paper, we study how the determination uncertainties of earthquake parameters (source depth and

Abstract For the past 30 years, the M8 medium-term earthquake prediction algorithm has been applied globally every six months in real time for identifying the areas where the world’s strongest earthquakes are most likely to occur. As of now, the statistics of the outcomes observed in the Global Test with a confidence exceeding 99% indicates fairly high efficiency of the forecasts based on the M8 algorithm

Abstract—The Central Asian and East Asian transitional zones are distinguished in Central and East Asia south of the Late Precambrian–Paleozoic fold belts of the Southern Russia and Kazakhstan and east of the Siberian Platform which are parts of the North Eurasian lithospheric plate. These transitional zones separate the plate from the Indian, Australian, and Pacific plates. The Central Asian zone

Abstract A new composite model is suggested for the frequency–magnitude relation of the earthquakes. The new model statistically reasonably describes the distribution in the range of weak and moderate events (the Gutenberg–Richter law) and in the range of strongest events (generalized Pareto law—one of the limiting laws in the extreme value theory). By the example of Japan and Kuriles, based on the

Abstract Recently, attempts have been made to take into account the fractal properties of seismicity when mapping the long-term rate of earthquakes. The paper touches upon the theoretical aspects of fractality and provides a critical analysis of its applications to the problems of seismic risk.

Abstract Geological and geomorphological criteria for the areas prone to the earthquakes with magnitudes M ≥ 7.0 are determined for the territory of the Hellenides located in the southern part of the Balkan Peninsula. Intersections of morphostructural lineaments identified by the morphostructural zoning method are considered as seismogenic structures. Geological and geomorphological parameters were

Abstract Algorithms for automated processing of seismic records are being constantly upgraded, and the tasks of data analysis are becoming more complex. Most algorithms require preliminary preparation of the data. This preprocessing is either very simple, such as frequency filtering, or highly sophisticated to extract specific properties of the signal. Adequate preprocessing can increase the efficiency

Kinematic generation of electrically conductive fluid by space-periodic flow is considered. The generated magnetic modes have a form of a product of three-dimensional field having the same spatial periodicity and a Fourier harmonic whose wave vector q is an arbitrary constant. We present the examples of computation of the modes associated with the maximum (over q) growth rates for a generic flow velocity

Abstract Heteroclinic cycle is an invariant of a dynamical system comprised of steady states (or more general invariant subsets) and heteroclinic trajectories. The behavior of a dynamical system with a heteroclinic cycle is intermittent: a typical trajectory stays for a long time close to a steady state while the transitions between the states occur much faster. Intermittency is present in various